1. Field of the Invention
The present invention relates to beverage mixing operations. More specifically, it relates to an apparatus and method for detecting when the syrup being dispensed toward a mixing chamber is depleted and then implementing a line clearing device for driving the syrup present in the line between the dispensing tank and the mixing tank into the mixing tank to alleviate the waste of the syrup in the line. Even more specifically, it relates to an apparatus and method wherein a pair of operating probes or sensors is present in the line, with the first probe being proximate to the dispensing tank and the second being proximate to the mixing chamber. Upon detection of air in the line by the first probe, the line pump is deactivated and a compressed gas is inserted into the line to drive the syrup contained therein towards the mixing chamber. When the second probe detects the presence of the gas in the line at its location, the compressed gas flow is halted, to allow for the refilling of the main dispensing tank and the subsequent flavor change and continuation of the bottling process.
More generally the inventive concept could be used in any pipeline operation where it is desired to change the type of fluid in a line from time to time without interruption of the flow to flush the line.. One such application would be in cross-country petroleum pipelines such as for blowing out all the diesel fuel from the line before beginning to pump a higher or lower distillate,
Thus it can be seen that the potential fields of use for this invention are myriad and the particular preferred embodiment described herein is in no way meant to limit the use of the invention to the particular field chosen for exposition of the details of the invention,
A comprehensive listing of all the possible fields to which this invention may be applied is limited only by the imagination and is therefore not attempted here. Some of the more obvious applications are mentioned herein in the interest of providing a full and complete disclosure of the unique properties of this previously unknown general purpose article of manufacture. It is to be understood from the outset that the scope of this invention is not limited to these fields or to the specific examples of potential uses presented hereinafter.
2. Description of the Prior Art
In the soft drink industry, during the bottling process, the syrup to be mixed with the water and CO.sub.2 is contained within a large tank, generally holding about 4000 gallons. This syrup is pumped through a line towards a mixing chamber, and then, after the mixing process, into the various cans, bottles, and the like used for marketing the finished product. When the dispensing tank is empty, the pump shuts down and the line between the dispensing and the mixing tank is flushed, and the syrup contained therein is dumped. In a conventional bottling plant the line between the dispensing and mixing tank is stainless steel tubing, about a two inches in diameter, and the length of the line is about 100 feet. This constitutes a waste of about 50 gallons of the syrup at every flavor change at the plant, these flavor changes generally occurring about four to six times a day. Applicant's present invention is addressed to this problem, allowing the utilization of the syrup in the line. Following hereinafter is a discussion of patents that bear on the dispensing and mixing of carbonated beverages.
Firstly, U.S. Pat. No. 3,945,536 issued on Mar. 23, 1976 to Gerald Doak discloses a sanitizing and cleaning device for pressurized soft drink systems. The device is attached to the existing lines between the tap heads and the CO.sub.2 tank and is filled with water and a sanitizing solution. When the tap heads are opened, the sanitizing solution is driven into the lines by the gas pressure until all of the solution is gone. A float then switches the pressure of the water in the device, which is then driven through the lines to flush them. This is in contrast to the present invention, which uses CO.sub.2 to drive the syrup in the lines towards the mixing chamber and includes a pair of sensors to monitor the presence and absence of the syrup that is being impelled.
Next is U.S. Pat. No. 4,467,941 issued on Aug. 28, 1984 to Benjamin R. Du. This discloses an apparatus and method for dispensing beverage syrup wherein air trap/filters are disposed in the line between the bag/box syrup containers and a low flow rate, positive displacement pump. Upon the detection of the presence of air in the dispensing line, the pump can be shut down or, additionally, a diverter valve can be activated to allow for a continuous flow while the empty container is replaced. Contrast this to applicant's invention wherein, upon detection of air downstream of the dispensing tank, the pump is not only shut down, but additionally a flow of pressurized gas is introduced into the line to substantially empty it of any remaining syrup further downstream of the pump.
In U.S. Pat. No. 4,632,275 issued on Dec. 30, 1986 to Charles K. Parks there is disclosed a palatability stabilizer that monitors the CO.sub.2 pressure in a postmix fountain drink dispensing system. The sensor is connected to a switch that disconnects power to the dispenser when the pressure falls below a predetermined level. This is unlike applicant's present invention in that the power to the fountain dispenser is shut off upon the switch or relay activation, and that the document does not teach introducing pressurized gas into the line for any reason.
Lastly, U.S. Pat. No. 5,072,859 issued on Dec. 17, 1991 to Ronald L. Wiley et al. discloses a beverage dispensing system with a purging feature. The purging feature functions as a result of a timer or thermometer, so as to prevent the warm soda water in the line from being dispensed, and it also functions when a light colored drink is dispensed after a dark colored drink to prevent inadvertent mixing of flavors. Contrast this to applicant's invention wherein CO.sub.2 is introduced under pressure to clear the line of syrup before the mixing chamber.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.